a review of the evidence of quit-lines: gaps in the evidence and how to close them dr lion shahab...
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A review of the evidence of quit-lines: gaps in the
evidence and how to close them
Dr Lion ShahabCRUK Health Behaviour Research CentreDepartment of Epidemiology & Public HealthUniversity College London
Overview
I. Why - the case for quitlines
II. What - evidence for the efficacy of quitlines
III. Where to – future questions to be answered
IV. How - state of the art in assessing smoking cessation interventions
Goals of Tobacco Control
To reduce the harm caused bytobacco use
To reduce participation in tobaccouse
To reduce the harmfulness oftobacco use
Reduce uptake
Increase cessation
I. Why – the case for quitlines
Approaches to Tobacco Control
Slama, 2004
Legislation & Policy
Basic Research Public Awareness
Values
Intervention Programmes
I. Why – the case for quitlines
To reduce the harm caused bytobacco use
To reduce participation in tobaccouse
To reduce the harmfulness oftobacco use
Reduce uptake
Increase cessation
Goals of Tobacco Control
To reduce the harm caused bytobacco use
To reduce participation in tobaccouse
To reduce the harmfulness oftobacco use
Reduce uptake
Increase cessation
I. Why – the case for quitlines
Predicted death-toll520500
340
0
100
200
300
400
500
1950 1975 2000 2025 2050Year
Cu
mu
lati
ve
to
ba
cc
o-r
ela
ted
de
ath
s (
mill
ion
s)
Current trend Uptake of smoking halved by 2020 Consumption halved by 2020
I. Why – the case for quitlines
Approaches to Tobacco Control – Impact on Prevalence
Low Reach High
Low
E
ffic
acy
H
igh
Number of people quitting
Efficacy x Reach = Impact on Prevalence
I. Why – the case for quitlines
Low Reach High
Low
E
ffic
acy
H
igh
Approaches to Tobacco Control – Impact on Prevalence
I. Why – the case for quitlines
Basic Research Public Awareness
Values
Legislation & Policy
Intervention Programmes
Advantages of quitlines
• Potential high efficacy– Can emulate individual counselling delivered on-site in smoking
cessation services– Flexibility of application – stand alone, or as addition to online
interventions, minimal/leaflet interventions or face-to-face support
• Potential wide reach– Easy access for users (flexible and near universal coverage)– Can attract additional smokers who would not normally seek help:
those living in remote areas, with physical disabilities, those fearing stigmatisation
• Cheaper than other high-intensity interventions– Possibility of computerised delivery
I. Why – the case for quitlines
Smokers
39 % Attempt to quit1
21 % use treatment1 18 % go ‘cold turkey’1
12 % buy NRT1 6 % get a prescription1 2.3 % use clinic1
Success 8 % 8% 15 % 11 % 4%Rates2
1 % + 0.5 % + 0.35 % + 0.08 % + 0.72
= 2.65 % stop smoking
Sources:
1 Smoking Toolkit Study
2 Cochrane Database
The path to smoking cessation
60 % Want to quit1
0.7 % use quitline1
I. Why – the case for quitlines
0.08% of 8.500.000 smokers = 6.800 ex-smokers ~ 15.000 life-years saved yearly
Telephone counselling for smokingcessation – a Cochrane review (2009)
• Types of telephone counselling– Proactive vs Reactive– Stand-alone vs Adjunctive
• RCT, quasi-randomised control trials• 6-months abstinence• 65 studies included with sample size of 73,000
participants
II. What - evidence for the efficacy of quitlines
• Study characteristics– Mostly from North America (52)– Older adults (average age 40)– Most evaluated proactive counselling (60)– Wide range of number of calls (1-12)– Call duration similar (10-20 min)– Mostly delivered by trained HP/counsellors
Telephone counselling for smokingcessation – a Cochrane review (2009)
II. What - evidence for the efficacy of quitlines
• Reactive telephone counselling– Single call
• Self-help vs. telephone counselling (1)• Different interventions (general vs. target) (2)
– Multiple calls• Reactive counselling at first call + self-help vs. further proactive
calls (9)
Telephone counselling for smokingcessation – a Cochrane review (2009)
II. What - evidence for the efficacy of quitlines
• Proactive telephone counselling– Multiple phone calls vs. self-help/minimal control (27)
Telephone counselling for smokingcessation – a Cochrane review (2009)
II. What - evidence for the efficacy of quitlines
II. What - evidence for the efficacy of quitlines
• Proactive telephone counselling– Multiple phone calls vs. self-help/minimal control (27)– Multiple phone calls + brief intervention/counselling vs.
brief intervention/counselling alone (9)
Telephone counselling for smokingcessation – a Cochrane review (2009)
II. What - evidence for the efficacy of quitlines
• Proactive telephone counselling– Multiple phone calls vs. self-help/minimal control (27)– Multiple phone calls + brief intervention/counselling vs.
brief intervention/counselling alone (9)– Multiple phone calls + pharmacotherapy vs.
pharmacotherapy along (9)
Telephone counselling for smokingcessation – a Cochrane review (2009)
II. What - evidence for the efficacy of quitlines
• Proactive telephone counselling– Multiple phone calls vs. self-help/minimal control (27)– Multiple phone calls + brief intervention/counselling vs.
brief intervention/counselling alone (9)– Multiple phone calls + pharmacotherapy vs.
pharmacotherapy along (9)– Comparisons by different counselling intensities
• 1-2 (9); 3-6 (28); 7+ (7)
Telephone counselling for smokingcessation – a Cochrane review (2009)
II. What - evidence for the efficacy of quitlines
Counselling intensity
0.8
0.9
1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1-2 3-6 7+
Number of sessions
Ris
k r
ati
o
• Proactive telephone counselling– Multiple phone calls vs. self-help/minimal control (27)– Multiple phone calls + brief intervention/counselling vs.
brief intervention/counselling alone (9)– Multiple phone calls + pharmacotherapy vs.
pharmacotherapy along (9)– Comparisons by different counselling intensities
• 1-2 (9); 3-6 (28); 7+ (7)
– Comparison by motivation to stop smoking• Smokers recruited for motivation (14) or not (30)
Telephone counselling for smokingcessation – a Cochrane review (2009)
II. What - evidence for the efficacy of quitlines
Impact of motivation
0.8
0.9
1
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
Motivation required Motivation not required
Recruitment criterion
Ris
k r
ati
o
• Review provides good evidence for effectiveness of telephone counselling
Telephone counselling for smokingcessation – a Cochrane review (2009)
II. What - evidence for the efficacy of quitlines
Type of counselling Evidence
Reactive Single call
Additional proactive support
Proactive Vs. self-help/minimal
Adjunct to behavioural support
Adjunct to pharmacotherapy
?
?
• Review provides good evidence for effectiveness of telephone counselling
• The more intensive, the better• No difference by motivation of smokers
Telephone counselling for smokingcessation – a Cochrane review (2009)
II. What - evidence for the efficacy of quitlines
Remaining empirical uncertainties
• Is reactive telephone counselling effective?
• What is the ideal number of proactive sessions?
• How best to increase uptake of telephone counselling?
III. Where to – future questions to be answered
Remaining empirical uncertainties
• Is reactive telephone counselling effective?– Problems: can’t use ‘pure’ RCT– What is appropriate control condition?– Elicit further calls?
III. Where to – future questions to be answered
Control (Self-help)
Intervention (generic)
Intervention (tailored)
1837
1837
1837
Remaining empirical uncertainties
• Is reactive telephone counselling effective?
• What is the ideal number of proactive sessions?
• How best to increase uptake of telephone counselling?
III. Where to – future questions to be answered
Remaining empirical uncertainties
• What is the ideal number of proactive sessions?– Problem: Have to make a priori assumptions about
cost-effectiveness– NNT=100 at £100 (1 %) assumed to be cost-effective at
QALY of £3000 (5 times better than average medical treatment)
III. Where to – future questions to be answered
1 session (£50)
2 sessions (£100)
3 sessions (£150)
4 sessions (£200)
NNT=400
NNT=200
NNT=100
NNT=50
Remaining empirical uncertainties
• Is reactive telephone counselling effective?
• What is the ideal number of proactive sessions?
• How best to increase uptake of telephone counselling?
III. Where to – future questions to be answered
Remaining empirical uncertainties
• How best to increase uptake of telephone counselling?– Enormous benefits
III. Where to – future questions to be answered
165 mil. smokers Attempt 66 mil. smokers Use QL 16.5 mil. Stop 1.8
Would safe 242.000 human beings from disability and early death
Remaining empirical uncertainties
• How best to increase uptake of telephone counselling?– Enormous benefits– Use of mass media and development of closer
relationship with health care system– Displaying phone numbers on tobacco or smoking
cessation products– Best assessed with quasi-experimental or RCT design
III. Where to – future questions to be answered
Remaining empirical uncertainties
• How best to increase uptake of telephone counselling?
III. Where to – future questions to be answered
Before After
Use
of
quit
-lin
es
Country A
Country B
Mass media campaign in Country B only
Net change
Remaining empirical uncertainties
• How best to increase uptake of telephone counselling?
III. Where to – future questions to be answered
Control (no info on QL)
Treatment (info on QL)
Control (NRT)
Treatment (NRT+ QL number)
Remaining methodological uncertainties
• Studies often did not provide information on adequate randomisation or allocation concealment
• Abstinence was not consistently validated and many used point-prevalence
• Studies were underpowered
IV. How - assessing smoking cessation interventions
10 common issues
1. inappropriate research question2. inadequate sample size3. inappropriate sample4. inadequate recruitment rate5. inappropriate study design6. poorly specified intervention and control7. inadequate implementation8. weak outcome measure9. failure to address potential bias10. over-claiming from the results
IV. How - assessing smoking cessation interventions
Key areas to consider
• Study sample• Study design• Outcome assessment
IV. How - assessing smoking cessation interventions
Study Sample
Priorities to be balanced• generalisation to
population of interest• safety• cost• practicability• red tape
Options to discuss• settings
– General practice– University– Community– Other
• size• method of recruitment• exclusion and inclusion
criteria
IV. How - assessing smoking cessation interventions
Study design
Priorities• internal validity• generalisation• practicability
Options to discuss
• design type– RCT (double-blind vs. unblinded)– Cluster randomised trial– Fractional factorial design– Quasi-experimental study– Longitudinal study– Cross-sectional survey
• intervention
• comparison condition(s)0
10
20
30
40
50
60
70
Wave 3 Wave 5 Wave 3 Wave 5
Pro
po
rtio
n o
f all
CD
TS
+ att
em
pte
rs (
%)
NRT use
NRT obtained OTC*
CC^UK
468 415111 99
9181
59
24
81
58
26
4 2
97
94
0
20
40
60
80
100
35 50 60 70 80 90 100
Age (Years)
% A
live
Cigarette smokers
10 years
IV. How - assessing smoking cessation interventions
The problem of causality
• Direction: Stay middle class to avoid schizophrenic episodes!?
• Higher order variables: If you want to live long, eat breakfast!?
Socioeconomic Status Schizophrenia
Breakfast Longevity
Smoking Behaviour
IV. How - assessing smoking cessation interventions
Outcome assessment
Priorities• theoretical significance• clinical significance• practicability
Options to discuss• smoking status• motivation to smoke• withdrawal symptoms
IV. How - assessing smoking cessation interventions
Some principles: sample
• always base size on ≥80% power for what would be a meaningful effect size (usually 1-5% difference in pivotal trials, i.e. those that will form basis for recommendations)
• usually use dependent smokers (not students)• recruit from community or healthcare settings• minimise exclusion criteria in pivotal trials, allow for up
to 50% wastage
IV. How - assessing smoking cessation interventions
Some principles: design
• where ethical and practicable use RCT but not at the expense of getting a sensible answer
• do not overcomplicate with too many factors• consider fractional factorial designs when trying to
deconstruct multi-component interventions
IV. How - assessing smoking cessation interventions
Some principles: outcome assessment
• pivotal studies require ≥6 months’ follow-up• use self-report of continuous abstinence verified by CO• do not use reduction• use intent to treat• aim for at least 70% follow-up rate• for withdrawal symptoms and craving use MPSS or
MNWS0
10
20
30
40
50
60
70
80
90
100
0 10 20 30 40 50
Weeks since quit date
Per
cen
t of q
uit
atte
mp
ters
Cumulative abstinence Long-term success in continuous abstainers at given week Relapse risk in given week
0
2
4
6
8
10
No COPD COPD
Mis
rep
ort
ing
sm
okin
g s
tatu
s (
%)
Location of filter vent holesLocation of filter vent holes outside ISO testing machine
IV. How - assessing smoking cessation interventions
Further reading
• Stead, L. F., Perera, R., & Lancaster, T. (2006). Telephone counselling for smoking cessation. Cochrane Database Syst.Rev., 3, CD002850.
• Borland, R. & Segan, C. J. (2006). The potential of quitlines to increase smoking cessation. Drug Alcohol Rev., 25, 73-78.
• West, R., et al., Outcome criteria in smoking cessation trials: proposal for a common standard. Addiction, 2005. 100(3): p. 299-303.
• Shiffman, S., R. West, and D. Gilbert, Recommendation for the assessment of tobacco craving and withdrawal in smoking cessation trials. Nicotine Tob Res, 2004. 6(4): p. 599-614.
• Strecher, V.J., et al., Web-based smoking-cessation programs: results of a randomized trial. Am J Prev Med, 2008. 34(5): p. 373-81.
Any questions?